1. Field of the Disclosure
The present disclosure relates to an organic light emitting display device, and more particularly, to an apparatus and method for driving an organic light emitting display device which facilitates to control a current flowing in a display panel to be lower than a current limit value.
2. Discussion of the Related Art
Due to recent multimedia developments, there is an increasing demand for a flat panel display. In order to satisfy this increasing demand, various flat panel displays such as liquid crystal display, plasma display panel, field emission display and organic light emitting display are practically used. Among the various flat panel displays, the organic light emitting display device has been attracted as a next-generation flat panel display owing to advantages of rapid response speed and low power consumption. In addition, the organic light emitting display device can emit light in itself, whereby the organic light emitting display device does not cause a problem related with a narrow viewing angle.
Generally, the organic light emitting display device displays an image by applying a data voltage to each pixel, and controlling a current flowing in an organic light emitting device according to a data current corresponding to the data voltage. For this, each pixel includes the organic light emitting device, a switching transistor, a driving transistor, and at least one capacitor.
An amount of light emitted from the organic light emitting device is proportional to a current amount supplied from the driving transistor. The switching transistor is switched according to a scanning signal, whereby the switching transistor supplies the data voltage supplied from a data line to the driving transistor. The driving transistor is switched according to the data voltage supplied from the switching transistor, whereby the driving transistor generates the data current based on the data voltage, and supplies the generated data current to the organic light emitting device. The capacitor maintains the data voltage supplied to the driving transistor for 1 frame period.
Generally, the organic light emitting display device according to the related art displays the image on a display panel by a data addressing method, wherein the data addressing method updates data of a current frame in data of a preceding frame displayed on the display panel. Accordingly, the organic light emitting display device according to the related art is disadvantageous in that an overcurrent momentarily flows in the display panel according to the image of preceding and current frames, as shown in FIG. 1.
In more detail, as shown in FIG. 1, the preceding frame has black data to be displayed on an upper region of the display panel, and white data to be displayed on a lower region of the display panel. The current frame has white data to be displayed on the upper region of the display panel, and black data to be displayed on the lower region of the display panel. If displaying the data of the preceding frame and the data of the current frame according to a vertical synchronous signal on the display panel by the data addressing method, the white data of the preceding frame and the white data of the current frame may be simultaneously displayed on the display panel during a partial addressing period of the current frame, whereby the overcurrent, which is higher than a current corresponding to the data for each frame, flows in the display panel.
Meanwhile, the organic light emitting display device according to the related art has a maximum allowable current value capable of flowing in the display panel so as to ensure reliability of device (or product) and safety from the overcurrent. For example, on assumption that the maximum allowable current value of the organic light emitting display device according to the related art is 10 A, if the current value flowing in the display panel according to the white data in each of the preceding and current frames shown in FIG. 1 is 10 A, the current value flowing in the display panel for almost all sections of the current frame is higher than the maximum allowable current value, 10 A.
In the organic light emitting display device according to the related art, a power supplier may be shut-down due to the overcurrent momentarily flowing in the display panel according to the image of preceding and current frames, whereby the image is not displayed on the display panel, thereby deteriorating the reliability of device (or product).